苹果园中凹唇壁蜂和紫壁蜂的生态位比较研究

COMPARATIVE STUDY ON THE NICHE OF OSMIA EXCAVATA ALFKEN AND O. JACOTI COCKERELL IN APPLE ORCHARDS

本文对凹唇壁蜂OsmiaexcavataAlfken和紫壁蜂O．jacotiCockerell的时间、空间、营养和筑巢生态位进行了研究。结果表明，在苹果园内人工释放和管理条件下，两种壁蜂在不同的资源序列上具有不同的生态位宽度、生态位重叠和不同程度的竞争关系。其中在营养上的竞争最为激烈，生态位重叠值和种间竞争系数分别高达0．9690和0．9994。日活动时间生态位竞争次之，其重叠值和种间竞争系数分别为0．7960和0．9350；时间生态位（季节）和空间生态位重叠值则分别为0．6500和0．6710，种间竞争系数为0．8213和0．8234；并且在人工巢管的选择上竞争性最小，生态位重叠值仅为0．4930，种间竞争系数为0．6052。凹唇壁蜂在营养生态位和时间生态位上较高的专一性均表现出其比紫壁蜂对苹果传粉作用更为显著。紫壁蜂在苹果开花后期的传粉作用较强。

The niche of the two native bees, Osmia excavata Alfken and O. jacoti Cockerell, released in apple orchards was comparatively studied in eastern China. The result indicates that the niche breadths (B), niche overlaps (C) and interspecific comptition coefficients (α) on time (day and seasonal), space, nutrition and nesting dimensions are different in the two species. The niche overlap and interspecific competition coefficient on nutrition between O. excavata and O. jacoti are significantly maximal, with values of 0. 9690 and 0. 9994 respectively. Those on day time dimension are 0. 7960 and 0. 9350. The measurements of the two species for space and seasonal time dimensions are relatively small and approximate, with C values of 0. 6500 and 0. 6710, and a values of 0. 8213 and 0. 8234 separately. These differentiations reduced the competitive relation between the two species. The competition for nesting tubes is the minimum, with a C value of 0. 4930 and a a value of 0. 6052. The trophic and time niche breadths of O. excavata greater than those of O Jactoti show that the former species is more effective in apple pollination for its higher specificity.